Problem on Second Law of Thermodynamics

Main Question or Discussion Point

A reversible engine works between three thermal reservoirs-A,B and C.The engine absorbs an equal amount of heat from the thermal reservoirs A & B kept at temperatures Ta and Tb respectively,and rejects heat to the thermal reservoir C kept at temperature Tc.The efficiency of the engine is $$\alpha$$ times the efficiency of the reversible engine,which works between the two reservoirs A & C.Prove that:Ta/Tb=(2$$\alpha$$-1)+2(1-$$\alpha$$)Ta/Tc